The present technology disclosed in the present specification relates to an imaging device which images a high dynamic range image using a low dynamic range imaging element.
According to the increasing bit-depth of imaging elements (imaging sensors) and the support for high bit-depths in displays, there is progress in the adoption of high dynamic range (HDR) images. An HDR image has a contrast ratio between the maximum brightness color and the minimum brightness color of, for example, 10000:1 or greater, and can realistically represent the real world. The HDR image has merits such as being capable of realistically representing shading, being capable of simulating exposure, and being capable of representing glare.
Examples of fields to which HDR technology can be adapted include electronics and devices which use an image captured from an imaging element (complementary metal oxide semiconductor (CMOS) sensors, charge coupled device (CCD) sensors), digital still cameras, video camcorders, medical image cameras, security cameras, digital cinematic filming cameras, binocular image cameras, and displays.
Various technologies that image a high dynamic range image using a low dynamic range imaging element are proposed.
For example, an imaging device which synthesizes an HDR image from a plurality of images with different exposures is proposed (for example, refer to Japanese Unexamined Patent Application Publication No. 2013-255301). However, when a one frame HDR image is synthesized from a plurality of frames, the following problems arise.
(1) Plural frames worth of memory is necessary.
(2) Delay time caused by capturing and processing of the plurality of frames.
(3) Motion blur of a moving object.